Try going here:
Cabela's Official Website - Quality Hunting, Fishing, Camping and Outdoor Gear at competitive prices.
Go to Archery, then tree stands and blinds and look for the Doghouse blind.
It comes in its own rucksac and has sprung steel hoops in it so all you have to do is take it out of the bag and it self erects.
You'll ave to pay postage and duty but mine worked out at about £110.00 and I wouldn't be without it now. Its high enough inside that your head isn't touching the top and very spaciouse at 5'x5'
Hope this helps.
Cheers
SteveHL